United States Patent [19]
`Hemmy et a1.
`
`|11111111111111lllllIllllllllllllllllllllllllllllllllllllllllllllllllllll
`5,098,383
`Mar. 24, 1992
`
`US005098383A
`Patent Number:
`[11]
`[45] Date of Patent:
`
`[54] DEVICE FOR ORIENTING APPLIANCES.
`PROSTHESES. AND INSTRUMENTATION
`IN MEDICAL PROCEDURES AND
`METHODS OF MAKING SAME
`[75] Inventors: David C. Hemmy. Elm Grove. Wis:
`Gregg S. Baker, Lake Forest; Paul B.
`Hafeli, El Toro, both of Calif.
`Artifax Ltd., Newport Beach, Calif.
`[73] Assignee:
`[21] Appl. No: 476,951
`[22] Filed:
`Feb. 8. 1990
`
`[51] Int. Cl.-‘ ............................................. .. AGIM 5/00
`.... .. 604/116; 606/96
`Field of Search ......................... .. 604/116; 606/96
`References Cited
`U.S. PATENT DOCUMENTS
`
`[56]
`
`3.542.022 11/1970 Bartnik .............................. .. 604/116
`3.941.127 3/1976 Froning ............................. .. 604/116
`4.360.028 11/1982 Barbier et a1. .
`4.427.005 1/1984 Tener ................................ .. 604/116
`4.436.684 3/1984 White .
`4.497.325 2/1985 Wedel ............................... .. 604/116
`4.580.561 4/1986 Williamson ....................... .. 604/116
`4.638.799 1/1987 Moore ............................... .. 604/116
`
`4.667.679 3/1987 Sahota ............................... .. 604/116
`
`
`
`4.723.544 2/1988 Moore et a1. 4.798.212 1/1989 Arana ................................ .. 604/116
`
`4.827.918 5/1989 Olerud .
`4.883.053 11/1989 Simon ................................ .. 604/116
`
`Primary Examiner-Paul J. Hirsch
`Attorney. Agent. or Firm-Finnegan. Henderson,
`Farabow, Garrett & Dunner '
`[57]
`ABSTRACT
`A guide, and methods for its manufacture and use, for
`use with a medical instrument whereby the instrument
`must contact a patient‘s tissue at a particular location.
`Given the speci?c patient’s tissue geometry, the general
`medical procedure and the speci?c practitioner‘s re
`quests, if any, a nonadjustable guide is speci?cally man
`ufactured such that one or more locations of the inven
`tion attaches to and/or abuts against a portion of patient
`tissue correctly orienting the device with respect to the
`patient‘s tissue geometry for purposes of performing the
`given medical task. The remaining geometric features of
`the device are dictated by the task for which it is de
`signed and other characteristics of the tissue.
`
`29 Claims, 4 Drawing Sheets
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`-1-
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`Smith & Nephew Ex. 1009
`IPR Petition - USP 7,534,263
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`US. Patent
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`Mar. 24, 1992
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`Sheet 1 of4
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`5,098,383 -
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`U.S. Patent
`US. Patent
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`Mar. 24, 1992
`Mar. 24, 1992
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`Sheet 2 of 4
`Sheet 2 of 4
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`5,098,383
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`U.S. Patent
`US. Patent
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`Mar. 24, 1992
`Mar. 24, 1992
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`Sheet 3 of 4
`Sheet 3 of 4
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`5,098,383
`5,098,383
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`US. Patent
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`Mar. 24, 1992
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`Sheet 4 of 4
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`5,098,383
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`49)
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`FIG. 5 i
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`5,098,383
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`DEVICE FOR ORIENTING APPLIANCES.
`PROSTHESES, AND INSTRUMENTATION IN
`MEDICAL PROCEDURES AND METHODS OF
`MAKING SAME
`
`BACKGROUND OF THE INVENTION
`A. Field of the Invention
`The present invention relates generally to devices
`used to establish proper orientation of medical instru
`ments during medical procedures. The present inven
`tion also relates to methods for producing devices used
`for orienting instruments during medical procedures.
`B. Description of the Prior Art
`There are many medical procedures which are tech
`nically demanding on the physician. More particularly,
`certain medical procedures require, for example, the
`cutting, drilling. reaming. or shaping of tissue, speci?
`cally. bone. When a practitioner performs these tasks. a
`high degree of accuracy in establishing the proper ori
`entation of medical instruments is required. In certain
`orthopedic and neurosurgical procedures these tasks
`can be extremely dif?cult because the practitioner must
`rely on locating a portion of the tissue. referred to as a
`landmark. and manually orient an instrument. appliance
`and/or prosthesis relative to that landmark.
`While some instrumentation is available for ?xing an
`apparatus to the tissue to aid the practitioner in orient
`ing the instrument. appliance and/or prosthesis relative
`to the landmark. such existing devices must be manually
`adjusted via. for example. screws to properly orient the
`instrument. appliance or prosthesis before the medical
`task is performed. This manual adjustment may require
`the concurrent use of scanning X-ray equipment.
`The inconvenience of requiring the practitioner, dur
`ing a medical procedure. to manually adjust such a
`device, while monitoring other equipment. to properly
`orient the instrument. appliance or prosthesis is a disad
`vantage of the existing devices. Disadvantageously.
`such adjustment requires the additional time ofthe prac
`titioner. of the operating facility in which the medical
`procedure is being performed and of the other person
`nel required to be present during the procedure to assist
`the practitioner, as well as a resulting additional expense
`to the patient. Most importantly. this disadvantage cre
`ates an added risk to the patient‘s life due to the addi
`tional time required to perform the procedure.
`Another disadvantage is the great potential for inac
`curate application of the instrument. appliance and/or
`prosthesis due to the adjustability of the existing de
`vices. For example. using such a device, the practitioner
`may be required to make several failed attempts to
`properly orient an appliance or prosthesis before
`achieving the proper orientation for the appliance or
`prosthesis. Additionally, due to the adjustability of the
`conventional devices. there is a high probability that the
`practitioner may never achieve an accurate orientation
`of the appliance or prosthesis.
`Still another disadvantage of the conventional de
`vices is the additional cost in having the scanner X-ray
`equipment and a quali?ed operator available during the
`procedure.
`SUMMARY OF THE INVENTION
`The object of the present invention is to provide a
`simple and direct way by which a medical instrument
`may be precisely guided to a point ofinterest within the
`body. Stated otherwise. the object ofthe present inven
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`tion is to provide the practitioner with the ability to
`establish orientation by use of a device which locates a
`point of interest. relative to a given landmark. and di
`rectly assists in performing the task at hand.
`Another object of the present invention is to manu
`facture distinct patient and medical task speci?c de
`vices. given information concerning the individual pa
`tient's tissue geometry at the given landmark location,
`the general medical procedure to be performed. the
`speci?c requests by the practitioner, if any, and the
`particular medical task at hand. The information con
`cerning the individual patient's geometry can be sup
`plied via one or more invasive or noninvasive modali
`ties, e.g., exploratory surgery. radiograph, computed
`tomography scan, nuclear magnetic resonance, photon
`emission tomography, etc. This collection of data prior
`to fabricating the patient speci?c devices of the present
`invention makes possible the necessary precision re
`quired by a practitioner when preforming a medical
`procedure. The patient speci?c devices of the present
`invention, in conjunction with appropriate data, estab
`lishes a high probability of accuracy for the practitioner
`when applying the instrument, appliance and/0r pros
`thesis for which the device was designed.
`Still another advantage of the present invention is the
`reduced time required to perform the medical proce
`dure, and resulting expense to the patient. Using the
`present invention, the practitioner merely has to locate
`the landmark surface and af?x the device to the loca
`tion. No further manual adjustment is required. The
`device then assists the practitioner in properly orienting
`the instrument, appliance and/or prosthesis and virtu
`ally eliminates any inaccurate application of the instru
`ment. appliance and/or prosthesis.
`Lastly, another object of the present invention is to
`minimize or to eliminate the need for scanning X-ray
`equipment and for a quali?ed operator of such equip
`ment to be present during the medical procedure.
`Additional objects and advantages of the invention
`will be set forth in part in the description which follows,
`and in part will be obvious from the description, or may
`be learned by practice of the invention. The objects and
`advantages of the invention will be realized and attained
`by means of the elements and combinations particularly
`pointed out in the appended claims.
`To achieve the objects and in accordance with the
`purpose of the invention, as embodied and broadly
`described herein, the device of the invention comprises
`a positioning means and an orienting means. The posi
`tioning means has a positioning surface, corresponding
`to a reference point on a surface of a landmark, deter
`mined prior to performing a medical task, for position
`ing the guide to remain in a ?xed location with respect
`to the landmark surface.
`The orienting means is ?xedly connected to the posi
`tioning means and guides an instrument to be used in the
`medical task to contact a patient tissue at an appropriate
`location, determinedjprior to performing the medical
`task, when the guide is in the ?xed location.
`An embodiment of the present invention includes the
`positioning means, the orienting means and a securing
`means. The positioning means has a positioning surface,
`corresponding to a plurality of reference points on a
`surface of a landmark, determined prior to performing
`the medical task, for positioning the guide to remain in
`a ?xed location with respect to the landmark surface.
`The positioning surface further comprises a portion
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`wherein the portion matches a plurality of points on the
`landmark surface.
`The orienting means is ?xedly connected to the posi
`tioning means and guides an instrument to be used in the
`medical task to contact a patient tissue at an appropriate
`location. determined prior to performing the medical
`task. when the guide is in the ?xed location. The orient
`ing means further comprises an orienting portion de?n
`ing a plurality of orienting holes. for guiding the instru
`ment to contact the patient tissue at the appropriate
`location when the instrument is inserted in one of the
`orienting holes.
`The securing means is connected to the positioning
`means. for removably attaching the device to the pa
`tient. The securing means includes a securing portion
`capable of attaching to, or being secured to. patient
`tissue, and optionally includes a hole through which a
`securing element may be inserted to contact patient
`tissue.
`20
`The present invention also is directed to a method of
`manufacturing a guide (e.g., a device according to the
`invention) out of a biocompatible material for perform
`ing a medical task during a medical procedure, wherein
`an instrument must contact a patient tissue at an appro- _
`priate location, and wherein a reference point, corre
`sponding to a surface of a patient tissue to be used as a
`landmark. is determined prior to performing the medi
`cal task. The method is characterized by the steps of
`(a) collecting data regarding a patient tissue geometry
`including the reference point corresponding to the land
`mark surface. via a modality;
`(b) collecting data concerning the medical procedure,
`the medical task to be performed and the instrument to
`be used during the task;
`(c) fabricating the positioning means from the bi
`ocompatible material characterized by a positioning
`surface corresponding to the patient tissue geometry
`and to the data. for positioning the guide in a ?xed
`location with respect to the landmark surface; and
`(d) fabricating the orienting means from the biocom
`patible material. ?xedly connected to the positioning
`means and corresponding to the data. for guiding the
`instrument to contact the patient tissue at the appropri
`ate location when the guide is placed in the ?xed loca
`tion.
`It is to be understood that both the foregoing general
`description and the following detailed description are
`exemplary and explanatory only and are not restrictive
`of the invention. as claimed.
`The accompanying drawings, which are incorpo
`rated in and constitute a part of this speci?cation, illus
`trate one embodiment of the invention and together
`with the description, serve to explain the principles of
`the invention.
`
`4
`DESCRIPTIOI\~ OF THE PREFERRED
`EMBODIMENT
`Reference will now be made in detail to the present
`preferred embodiment of the invention. examples of
`which are illustrated in the accompanying drawings.
`Wherever possible, the same reference numbers will be
`used throughout the drawings to refer to the same or
`like parts.
`The preferred embodiment of the present invention.
`as depicted in FIG. 1, is primarily designed for a proce
`dure of drilling into bone. The present invention may
`also be used for other medical tasks, including but not
`limited to the cutting, reaming and shaping of tissue. In
`the preferred embodiment of the present invention.
`given a predetermined location of the body wherein a
`medical task is to be performed, a three-dimensional
`tissue geometry is constructed via a noninvasive
`method, e.g., radiograph, computed tomography scan,
`nuclear magnetic resonance or photon emission tomog
`raphy. An invasive method, for example. exploratory
`surgery. also may be performed to gather the three‘di
`mensional tissue geometry.
`Given the speci?c patient's tissue geometry. the gen
`eral medical procedure and the speci?c practitioner's
`requests, if any, the preferred embodiment of the pres
`ent invention is speci?cally manufactured such that one
`or more locations ofa device according to the invention
`attaches to and/or abuts against a speci?c surface in
`order to correctly orient the device with respect to the
`patient's tissue geometry for purposes of performing the
`given medical task. The remaining geometric features of
`the device are dictated by the task for which it is de
`signed and other characteristics of the tissue. For exam
`ple, the preferred embodiment of the present invention
`may contain one or more holes used by a practitioner
`for establishing the location of drill holes in the bone for
`the purpose of performing certain medical tasks with
`conventional medical instruments. The device accord
`ing to the present invention also‘ may contain one or
`more openings, surfaces, contours, templates or indica
`tors used by the practitioner for establishing the loca
`tion of cut planes, drill holes, shaping surfaces or refer
`ence vectors for the purpose of performing a variety of
`medical tasks with a variety of medical instruments,
`e.g., emplacement of a supporting plate.
`Referring to the accompanying ?gures, FIGS. 1-3, it
`may be seen that the preferred embodiment of the pres
`ent invention provides a guide 10', for performing a
`medical task during a medical procedure, wherein an
`instrument must contact a patient tissue at appropriate
`locations, and wherein a plurality of reference points,
`corresponding to surfaces to be used as landmarks, are
`determined prior to performing the medical task. A
`landmark may be, for example, a unique surface of a
`patient tissue and/or an installed synthetic surface. This
`embodiment was designed to properly orient screw
`hole locations and depth for insertion of screws into the
`bony tissue surrounding the spine for securing a plate
`(not shown) to three vertebras of the spinal column
`using unique surfaces of a patient tissue as landmarks.
`In addition to the guide 10 of the present embodi
`ment, the medical instruments required to perform this
`task are, for example, screws, cross pins, guide sleeves,
`a drill with stop, a tap. a screwdriver and a nut driver.
`The plurality of reference points, corresponding to
`surfaces of a patient tissue to be used as landmarks, are
`determined by means of a method for determining a
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`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is an isometric projection of an embodiment of
`the present invention.
`FIG. 2 is a top view of the embodiment.
`FIG. 3 is a side view of the embodiment.
`FIG. 4 is a side view of the embodiment placed adja
`cent to a spine.
`‘
`FIG. 5 is a side view of the embodiment with an
`orienting surface.
`FIG. 6 is a cross pin with stop to be inserted through
`a single positioning hole depicted in FIG. 2.
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`three dimensional patient tissue geometry as described.
`for example. in 5 Radiology of the Skull and Brain.
`Technical Aspects of Computed Tomography (i980).
`The body is subjected to radiant energy to produce
`radiant energy responses internal to the body. The radi~
`ant energy responses are detected to obtain representa
`tions of substances at locations internal to the body.
`Finally. a set of three dimensional coordinates is gener
`ated and de?nes a three dimensional representation of
`one or more selected landmarks. which in this particu
`larly case are internal to the body.
`Once the three dimensional patient tissue geometry of
`the landmark surfaces is generated. the preferred em
`bodiment of the present invention may be manufac
`tured. Prior to fabricating the device of the preferred
`embodiment, using the specific patient tissue geometry’.
`other data concerning the procedure to be performed,
`for example, the placement of screw hole locations on
`the patient tissue. as well as the angle and depth of the
`screw holes is determined. Finally, after this informa
`tion concerning the procedure and any additional infor
`mation from the practitioner is obtained. the guide 10
`can be fabricated from biocompatible material.
`In accordance with the preferred embodiment. the
`present invention comprises a positioning means. an
`orienting means and a securing means. The orienting
`means and the securing means are fixedly connected to
`the positioning means in, for example. a unitary body or
`monolithic structure.
`-
`As illustrated in FIG. 4. the proximal end ofthe guide
`10 is determined by the location of the guide 10 with
`respect to the location of the head. That side of the
`guide 10. closest to the head, when the guide 10 is
`placed on the spinal column. is referred to as the proxi
`mal end.
`In accordance with the preferred embodiment. the
`guide 10 as illustratively shown is FIGS. 1 and 2. com
`prises a posterior surface 20. Also depicted in FIGS. 1
`and 2 is the guide 10 which defines numerous hollow
`openings from the posterior surface 20. through the
`guide 10. to a positioning surface 12. In FIG. 1 these
`openings include a proximal hollow portion 18. a view
`ing hollow portion 19 and a plurality of orienting holes
`24 a-c on the right side ofthe guide 10 and a plurality of
`orienting holes 26 0-: on the left side of the guide 10.
`All of these openings are fabricated in the guide 10 in
`accordance with instructions concerning the medical
`task to be performed and the specific patient tissue ge~
`ometry adjacent to where the task is going to be per
`formed. Most important to the present embodiment. the
`proximal hollow portion 18, de?ned by the guide 10,
`permits the practitioner to confirm proper placement of
`the positioning surface 12 on a landmark surface. The
`viewing hollow portion 19 allows the practitioner to
`view a patient tissue adjacent to landmark surfaces.
`In accordance with this embodiment of the present
`invention, the positioning means is characterized by
`having the positioning surface 12. As illustratively
`‘shown in FIGS. 1 and 3, by way of example and not
`limitation. the positioning surface 12 is provided, a por~
`tion of which corresponds to the plurality of reference
`points ofthe patient tissue geometry, for positioning the
`guide 10 to remain in a fixed location with respect to the
`landmark surfaces. The positioning surface 12 includes
`a surface portion 13 and two positioning portions 28 and
`36. The positioning portions respectively correspond to
`subgroups of the plurality of reference points on the
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`surface of a patient tissue previously referred to as sur
`face landmarks.
`The proximal positioning portion 28 is located at the
`proximal end on the guide 10. The distal positioning
`portion 36. located at the distal end of the guide 10.
`substantially axially spaced from the proximal position
`ing portion 28. corresponds to a subgroup of the plural
`ity of reference points which form. for example, a con
`tour surface which matches or compliments a landmark
`surface.
`The proximal positioning portion 28 of the position
`ing surface 12. as depicted in FIG. 1. by way of example
`and not limitation, comprises the proximal positioning
`surfaces 14 and 15. The proximal positioning surfaces 14
`and 15. varying in depth from the surface portion 13 by
`proximal offset positioning portions 16 and 17 respec
`tively. contain sufficient geometric features to consti
`tute a surface or contour which matches and/or com
`plements a landmark surface, or at least to constitute a
`surface that mates to or engages the landmark. The
`varying depth of each of the offset proximal positioning
`portions 16 and 17 is determined by the three dimen
`sional patient tissue geometry. This enables the position
`ing surface 12. including the proximal positioning sur
`faces 14 and 15. to lie adjacent to and/or abut against
`landmark surfaces.
`As stated earlier. the proximal hollow portion 18,
`defined by inside surfaces 29, 31, and 32 of the guide 10,
`illustrated in FIG. 1. permits the practitioner to estab
`lish proper placement of the positioning surface 12 of
`the guide 10, including the proximal positioning portion
`28. on the spinal column adjacent to the location on the
`spinal column where the medical task is to be per
`formed. The inside surfaces 29. 31 and 32 of the proxi
`mal hollow portion 18 contact a surface of a landmark.
`The distal positioning portion 36 of the positioning
`surface 12 is V-shaped and comprises a two-sided sur
`face including a right-side distal positioning surface 37
`and a left-side distal positioning surface 38. The V
`shaped distal positioning portion 36 comprised of the
`right-side distal positioning surface 37 and the left-side
`distal positioning surface 38, also contain sufficient geo
`metric features to constitute a surface or contour which
`matches and/or complements another landmark sur
`face, or a surface which engages the landmark surface.
`As stated earlier, the viewing hollow portion 19 of
`the guide 10 allows the practitioner to view a patient
`tissue adjacent to the landmark surfaces corresponding
`to the positioning portions 28 and 36 of the positioning
`surface 12 of the guide 10. Further variation of the
`present invention would be apparent to one skilled in
`the art by adding multiple positioning surfaces and/or
`multiple contours to the present embodiment.
`In accordance with the present embodiment, as de
`picted in FIGS. 1 and 2, the orienting means, ?xedly
`connected to the positioning means, is characterized by
`having an orienting portion defining a plurality of ori
`enting holes, 24 ,a-c and 26 a-c, for guiding instruments
`inserted in the orienting holes 24 a-c and 26 a-c to
`contact the patient tissue at the appropriate locations
`when the guide is in the ?xed location. In addition to the
`orienting holes 24 a-c and 26 a-c, FIG. 1 depicts the
`reference vector lines corresponding to each of the
`orienting holes 24 a-c and 26 41-0. These vectors indi
`cate the predetermined angles the orienting holes 24 a-c
`and 26 0-0 manufactured in the guide 10. In this embodi
`ment the orienting holes 24 a-c and 26 0-: guide a drill
`bit to contact the patient tissue at the appropriate loca
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`tions. indicated by the reference vectors. adjacent to the
`positioning surface 12. and to drill a hole into the patient
`tissue at the correct angle and depth. Additionally. the
`orienting holes 24 0-0 and 26 a-c guide other instru
`ments to perform other tasks during the medical proce
`dure. e.g.. guiding screws to the appropriate tissue loca
`tions.
`It will be apparent to those skilled in the art that
`various modi?cations and variations can be made in the
`orienting portion of the present invention and in con
`struction of the orienting portion without departing
`from the scope or spirit ofthe invention. As an example,
`as illustratively shown in FIG. 5. the orienting portion
`may include an orienting slit 45 to guide a saw to
`contact an appropriate patient tissue location. The ori
`enting slit 45 may contain a proximal orienting slit sur
`face 46, a distal orienting slit surface 47 and a lower
`orienting slit surface 48 which form a miter box-type
`groove in the upper surface 20 of the guide 10 to guide
`a saw inserted in the groove to contact a patient tissue
`at the appropriate location. In a second example. the
`orienting portion may include an orienting surface 49 to
`guide a saw, placed adjacent to the orienting surface 49,
`to contact a patient tissue at the appropriate location. In
`still another example. the orienting portion may de?ne
`an orienting template with proximal and distal template
`surfaces. to guide an instrument to contact a patient
`tissue at the appropriate location. It would be apparent
`to one skilled in the art that the orienting portion may
`include any combination of orienting holes and/or ori
`enting surfaces.
`In accordance with the present invention. the secur
`ing means. ?xedly connected to the positioning means.
`is for removable attachment of the positioning surface
`adjacent to the patient tissue used as landmarks. As an
`example. the present embodiment characterizes the
`securing means as including a securing portion which
`defines a plurality of securing holes. As illustratively
`shown in FIG. 2. by way of example and not limitation.
`securing holes 21 a-b and 22 0-12 are located at opposite
`ends of the guide. two at the proximal end 21 a-b and
`two at the distal end 22 a-b. above the respective posi
`tioning portions 28 and 36. Securing devices. for exam
`ple. a cross pin with a stop 23 depicted in FIG. 6, may
`be inserted through the securing holes 21 a-b and 22 a-b
`at a predetermined angle to contact the patient tissue
`adjacent to the landmarks and to secure the guide 10 to
`the patient tissue. It will be apparent to those skilled in
`the art that various modifications and variations can be
`made in the securing means of the present invention and
`in construction of the securing means portion without
`departing from the scope or spirit of the invention.
`Now an example of a medical procedure using the
`preferred embodiment of the present invention will be
`described. As discussed earlier, prior to performing the
`procedure, the patient‘s three dimensional tissue geome
`try, corresponding to the location along the spinal col
`umn where a standard metal plate is to be secured to
`fuse two or more vertebras together, is determined via
`a noninvasive means. e.g., a standard CT scan. Many
`components of the present invention are designed for
`the individual patient‘s tissue geometry.
`The metal plate described above is secured with
`screws. The placement of the screws, screw hole orien
`tation and depth. is provided at each screw location
`with the custom instrumentation of the present inven
`tion. Additionally, each screw is manufactured to a
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`prescribed length and the plates are manufactured to
`match the final screw placement in the spinal column.
`Generally. the instrumentation required to perform
`the procedure includes:
`1) The guide of the preferred embodiment of the
`present invention manufactured from biocompati
`ble. autoclaveable plastic which functions to orient
`the screw holes to speci?c bony tissue landmarks.
`2) Cross Pins: For example. stainless steel pins with
`depth stops to secure the guide at proximal and
`distal locations.
`3) Guide sleeves: Cylindrical plastic sleeves to be
`installed in the guide to establish screw hole orien
`tation and depth.
`4) Drill with Stop: Conventional surgical drill with
`chuck and pin cutter, to drill the screw holes to a
`prescribed orientation and depth.
`5) Tap: Standard instrumentation used to thread a
`screw hole with 5 mm incremental markings.
`6) Screwdriver: Standard instrumentation with 5 mm
`incremental markings.
`7) Nut driver: Standard instrumentation.
`To begin the procedure, the practitioner clears the
`soft tissue from the landmark locations. The practitio
`ner then determines the spinous process, referred to as
`the proximal landmark, adjacent to which the proximal
`positioning portion 28 and the proximal hollow portion
`18 of the guide 10 are to be fixed. The next step would
`be to place the drill guide proximal contour positioning
`portion 28 over the preselected spinous process. The
`practitioner would then press firmly on the posterior
`surface 20 ofthe guide 10 over the spine to ensure that
`the guide 10 rests properly at both the proximal land
`mark, adjacent the proximal contour positioning por
`tion 28, and at a distal landmark, adjacent the distal
`contour positioning portion 36. substantially axially
`spaced from the proximal landmark along the spine. If
`the guide 10 appears unstable, then the practitioner
`would remove the guide 10, remove any impediments,
`e.g., soft tissue interfering with placement of the guide
`10. and replace the guide 10 to its proper position. Con- ,
`firming proper placement of the guide 10 using the
`proximal hollow portion 18 and holding the guide 10
`stable on the spine. the next step is to insert the proximal
`and distal cross pins in the positioning holes 21 0-17 and
`22 a—b to contact the patient tissue and to secure the
`guide 10.
`Now that the guide is secured in place, the practitio
`ner would proceed by placing the guide sleeves in the
`orienting holes 24 0-0 and 26 a-c matching each sleeve
`to its correct location. Using the viewing hollow por
`tion 19 to view the patient tissue during the task, the
`practitioner would then proceed, using a proper drill bit
`to accommodate a standard 2 mm Steinman pin, by
`inserting the bit successively into each guide sleeve and
`drilling a I of the full depth hole into the bone adjacent
`to the orienting holes 24 a-c and 26 0-0. Standard 2 mm
`Steinman pins are then inserted through each of the
`guide sleeves into the holes in the bony tissue. To ensure
`that the final placement of the screws and plates will be
`accurate the practitioner may then con?rm proper ori
`entation of the screw holes in the bony tissue radio
`graphically.
`Once confirming the orientation of the holes, the
`practitioner would then redrill the holes to full depth.
`Once all of the holes are completed, the guide sleeves
`are removed from the orientation holes 24 0-0 and 26
`a-c of the guide 10. The standard tap is then succes
`
`65
`
`40
`
`50
`
`55
`
`-9-
`
`

`
`5
`
`5,098,383
`1O
`7. The guide of claim 1 further comprises securing
`sively placed through each of the orientation holes 24
`means. connected to the positioning means. for attach
`0-( and 26 0-0 to thread the screw holes to the pre
`ing the positioning surface to the landmark surface.
`scribed depth. The conventional screws 5 a—c. depicted
`8. The guide of claim 7 wherein the securing means
`in FIG. 4. which are specially manufactured to the
`includes a securing portion de?ning a securing hole.
`prescribed length are then successively inserted
`9. The guide of claim 1 further comprises securing
`through the orientation holes 24 0-0 and installed to the
`prescribed depth. The same procedure would then be
`means. connected to the positioning means. for remov
`ably attaching the positioning surface to the landmark
`performed to install similar screws using orientation
`surface
`hole 26 a-c. The guide 10 is then detached from the
`spinal column by removing the cross pins.
`10. The guide of claim 9 wherein the securing means
`includes a securing portion de?ning a securing hole.
`Followed by the installation of a spacer. a lower nut
`11. A guide for use with an instrument in performing
`is secured to each ofthe screws. The practitioner would
`a medical task during a medical procedure on a patient
`then install the custom metal plates onto the lower nuts
`noting the left and right locations Finally to complete
`tissue. wherein the instrument must contact a patient
`the task, the practitioner would secure the plates with